Display panel using laser cutting technology and the mother substrate thereof

ABSTRACT

A display panel using laser cutting technology and a mother substrate thereof are provided. The display panel comprises two base plates opposite to each other, a sealant and a buffering metal layer. The sealant is disposed between the two base plates. The buffering metal layer formed on the inside surface of at least one of the two base plates is disposed along the sealant. At least a portion of the buffering metal layer is positioned outside the sealant. There is a first distance between the rim of the buffering metal layer and the edge of the base plate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 12/292,065, filed Nov. 12, 2008 and entitled“DISPLAY PANEL USING LASER CUTTING TECHNOLOGY AND THE MOTHER SUBSTRATETHEREOF”. This application claims the benefit of Taiwan ApplicationSerial No. 97115424, filed Apr. 25, 2008. U.S. patent application Ser.No. 12/292,065 and Taiwan Application Serial No. 97115424 areincorporated herein in their entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a display panel and a mothersubstrate thereof, and more particularly to a display panel which hasbuffering metal layer and is capable of being cutting by laser and amother substrate thereof.

2. Description of the Related Art

Diamond knife, water cutter knife and laser cutting are often used inglass cutting technology. During laser cutting, the heat generated by alaser source breaks glass molecular bond first and then the brokenmolecules are cooled down by a cooling device next. Then, the glass isdivided due to thermal expansion and contraction.

Referring to both FIG. 1A and FIG. 1B. FIG. 1A illustratively shows aLCD mother substrate cut by a conventional laser cutting technology.FIG. 1B illustrates an enlarged portion of the top and the bottom mothersubstrates and the sealant of FIG. 1A, and the portion close to apredetermined laser cutting line. The LCD mother substrate 10 typicallycomprises a first mother substrate 11, a second mother substrate 13assembled with the first mother substrate 11 by a sealant 16, and aliquid crystal layer (including numerous LC molecules) disposedtherebetween. The first mother substrate 11 and the second mothersubstrate 13, for example, are respectively a mother substrate having acolor filter layer and a mother substrate having many transistors. ManyLCD panels 15 can be formed by laser cutting the first mother substrate11 and the second mother substrate 13. Each display panel 15 has adisplay area 51 and an IC bonding area 53, wherein the sealant 16 isdisposed around the display area 51. As indicated in FIG. 1A, the laserlight C cuts the first mother substrate 11 along the predetermined lasercutting line 19 of the first mother substrate 11.

Referring to FIG. 1B, a metal black matrix or a resin black matrix 17 isnormally disposed between the first mother substrate 11 and the sealant16. In addition to the resin black matrix 17, the organic materiallayers disposed under the first mother substrate 11 (i.e. comprising thecolor filter layer) could further include an overcoat 18. During lasercutting, the laser beam 30 is normally deformed into a long ellipsewhose width D30 ranges between about 1˜1.4 mm. Also, the distancebetween the black matrix 17 and the predetermined laser cutting line 19,and the distance D16 (illustrated in FIG. 1A) between the edge of thesealant 16 and the predetermined laser cutting line 19 generally rangebetween about 0.3˜0.5 mm. As the distance may further be reduced to 0.2mm in some special designs, the width D30 of the laser beam 30 isobviously larger than the distance. As laser cutting is a heat treatmentprocess, the materials underneath the glass such as the sealant 16 andthe organic material layer(s) will be affected by the heat generatedduring laser cutting on the first mother substrate 11 or the secondmother substrate 13 made from glass. For example, the organic materiallayer(s) such as the resin black matrix 17 and the overcoat 18 of thefirst mother substrate 11 of FIG. 1B which can only resist about 200° C.will be affected. Furthermore, along with the advance in the industry,the distance D16 between the sealant 16 and the edge of and thepredetermined laser cutting line 19 becomes shorter and shorter, thefirst mother substrate 11 and the second mother substrate 13 also becomethinner and thinner. When laser cutting is performed on a thin glassmother substrate, the heat radiated downwards will severely affect thesealant 16, the resin black matrix 17 and the overcoat 18 (the organicmaterial) which are positioned close to the cutting line. The sealant 16and the organic material may be melted, cracked or peeled off, hence theLCD panel 15 is damaged and the yield of production is deteriorated.

Thus, how to avoid the heat of the laser beam damaging the sealant 16 orthe organic materials of the mother substrate close to the laser cuttinglines has become an imminent issue to be resolved.

SUMMARY OF THE INVENTION

The invention is directed to a display panel using laser cuttingtechnology and a mother substrate thereof. With the disposition of abuffering metal layer, the heat of the laser light radiated under themother substrate during laser cutting will not damage the sealant or theorganic material disposed close to the cutting line. Thus, themanufactured display panel has excellent quality and product yield isincreased.

According to a first aspect of the present invention, a display panelcomprising a first base plate and a second base plate which are disposedopposite to each other, a sealant and a buffering metal layer isprovided. The sealant is disposed between the two base plates. Thebuffering metal layer formed on the inside surface of at least one ofthe two base plates is disposed along the sealant. At least a portion ofthe buffering metal layer is positioned outside the sealant. There is afirst distance between the rim of the buffering metal layer and the edgeof the base plate.

According to a second aspect of the present invention, a liquid crystaldisplay (LCD) mother substrate comprising many LCD panels is provided.The LCD mother substrate further comprises a first mother substrate anda second mother substrate which are opposite to each other, a sealantand a buffering metal layer. Each mother substrate has an inside surfaceand an outer surface. The inside surfaces of the two mother substratesare opposite to each other, and the outer surfaces of the two mothersubstrates respectively have a predetermined cutting line. The sealantis disposed between the inside surfaces of the two mother substrates andpositioned on the inner side of the corresponding predetermined cuttingline. The buffering metal layer formed on the inside surface of at leastone of the two mother substrates is disposed along the sealant. At leasta portion of the buffering metal layer is positioned outside thesealant. There is a first distance between the rim of the bufferingmetal layer and the predetermined cutting line.

In the embodiments of the invention, the first distance between the rimof the buffering metal layer and the edge of a base plate (or apredetermined cutting line) is smaller than the second distance betweenthe rim of a resin black matrix and the edge of a base plate such as acolor filter base plate. The first distance is at least 5 μm; forexample, the first distance ranges between 5˜300 μm, 5˜200 μm, or 5˜100μm. When the invention is used in laser cutting a thin base plate or ina structural design where the distance between the sealant and thepredetermined cutting line is very tiny, the first distance between therim of the buffering metal layer and the edge of the base plate ispreferably set as 5˜20 μm to avoid the sealant or the organic materialdisposed close to the cutting line being damaged by laser heat.

The invention will become apparent from the following detaileddescription of the preferred but non-limiting embodiments. The followingdescription is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A (Prior Art) illustratively shows a LCD mother substrate cut by aconventional laser cutting technology;

FIG. 1B (Prior Art) illustrates an enlarged portion of the top and thebottom mother substrate and the sealant of FIG. 1A, and the portionclose to a predetermined laser cutting line;

FIG. 2A shows a perspective of an LCD mother substrate according to afirst embodiment of the invention;

FIG. 2B shows a cross-sectional view along the segment AA′ of FIG. 2A;

FIG. 3 shows a cross-sectional view of a display panel according to thefirst embodiment of the invention;

FIG. 4 shows a top view of the buffering metal layer and the sealant ofthe first embodiment of the invention on a color filter mothersubstrate;

FIG. 5 shows a top view of the buffering metal layer and the sealantformed on a transistor mother substrate according to the firstembodiment of the invention;

FIG. 6 shows a cross-sectional view of an LCD mother substrate close toa predetermined laser cutting line according to the second embodiment ofthe invention; and

FIG. 7 shows a partial cross-sectional view of a single LCD panel formedby cutting the LCD mother substrate of the second embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

A display panel using laser cutting technology and a mother substratethereof are disclosed in the invention. The display panel comprises twobase plates opposite to each other, a sealant and a buffering metallayer. The two base plates comprise a first base plate and a second baseplate. The sealant is disposed between two base plates. The bufferingmetal layer disposed along the sealant is formed on the inside surfaceof at least one of the two base plates. At least a portion of thebuffering metal layer is positioned outside the sealant. There is afirst distance between the rim of the buffering metal layer and the edgeof the base plate. The embodiments disclosed below are practicalembodiments of the display panel and the mother substrate thereofaccording to the invention. However, the following embodiments are forelaborating the invention not for limiting the scope of protection ofthe invention which is defined in the claims of the invention. Thus, thespecification and the drawings are to be regarded as an illustrativesense rather than a restrictive sense. Additionally, the drawings usedfor illustrating the embodiments and applications of the presentinvention only show the major characteristic parts in order to avoidobscuring the present invention.

First Embodiment

Referring to FIGS. 2A and 2B. FIG. 2A illustratively shows a LCD mothersubstrate according to a first embodiment of the invention. FIG. 2Bshows a cross-sectional view along the segment AA′ of FIG. 2A. The LCDmother substrate 1000 comprises two mother substrates opposite to eachother, a sealant 150 and a buffering metal layer 170. The two mothersubstrates are a color filter mother substrate 1100 and a transistormother substrate 1300 respectively, and the outer surfaces of the twomother substrates both have two predetermined laser cutting lines L0 andL2. Besides, the outer surface of the color filter mother substrate 1100further has a predetermined laser cutting line L1. The sealant 150 isdisposed between the two mother substrates 1100 and 1300 and positionedon the inner side of the corresponding predetermined laser cutting linesL0, L1 and L2. The buffering metal layer 170 is formed on the insidesurface 1100′ or 1300′ of at least one of the two mother substrates 1100and 1300, and there is a first distance D170 between the rim of thebuffering metal layer 170 and the predetermined laser cutting line L0.

The LCD mother substrate 1000 comprises many display panels 100. Eachdisplay panel 100 is defined by the predetermined laser cutting linesL0, L1 and L2. Each display panel 100 has a display area A100. Thesealant 150 and the buffering metal layer 170 are disposed along the rimof each display area A100. Furthermore, the sealant 150 and thebuffering metal layer 170 are disposed between each display area A100and the predetermined laser cutting lines L0, L1 and L2. In the presentembodiment of the invention, the distance between the buffering metallayer 170 and the corresponding predetermined laser cutting lines L0, L1and L2 is defined as the first distance D170. The partial area 170 a ofthe buffering metal layer 170 is disposed along the sealant 150, and atleast another partial area 170 b of the buffering metal layer 170 ispositioned outside the sealant 150.

Referring to both FIG. 2A and FIG. 3. FIG. 3 shows a cross-sectionalview of a display panel according to the first embodiment of theinvention. Many display panels 100 are formed after the LCD mothersubstrate 1000 is cut. The display panel 100 comprises a color filterbase plate 110 and a transistor base plate 130 opposite to the colorfilter base plate 110. The color filter base plate 110 is formed bycutting the color filter mother substrate 1100 along the correspondingpredetermined laser cutting lines L0, L1 and L2. Similarly, thetransistor base plate 130 is formed by cutting the transistor mothersubstrate 1300 along the corresponding predetermined laser cutting linesL0 and L2. Thus, FIG. 3 is a cross-sectional view of cutting the LCDmother substrate 1000 of FIG. 2A along the segment BB′, and the edge110′ of the color filter base plate 110 of FIG. 3 is defined by cuttingthe color filter mother substrate 1100 along the predetermined lasercutting line L2.

The display panel 100 after cutting is illustrated in FIG. 3. Eachdisplay panel 100 has a sealant 150, a buffering metal layer 170 and adisplay area A100. The sealant 150 is disposed between the two baseplates 110 and 130 for fixing the two base plates 110 and 130. In thepresent embodiment of the invention, the buffering metal layer 170 isformed on the inside surfaces 112 and 132 of the two base plates 110 and130. Take the color filter base plate 110 for example. The bufferingmetal layer 170 formed on the inside surface 112 of the color filterbase plate 110 is positioned between the color filter base plate 110 andthe sealant 150. The first distance D170′ between the rim of thebuffering metal layer 170 and the edge 110′ of the color filter baseplate 110 as indicated in FIG. 3 is substantially identical to the firstdistance D170 between the rim of the buffering metal layer 170 and thepredetermined laser cutting line L2 as indicated in FIG. 2B. Also, thereis a third distance D150′ between the rim of the sealant 150 and theedge 110′ of the color filter base plate 110, and the first distanceD170′ is smaller than the third distance D150′.

As shown in FIG. 3, a liquid crystal layer 190 is contained among thecolor filter base plate 110, the transistor base plate 130 and thesealant 150. The inside surface 1100′ of the color filter mothersubstrate 1100 (illustrated in FIG. 2B) has a color filter layer. Theinside surface 1300′ of the transistor mother substrate 1300(illustrated in FIG. 2B) has many transistors arranged in an array andmany metal layers connected to the transistor.

Thus, after cutting, the inside surface 112 of the color filter baseplate 110 has a color filter layer, while the inside surface 132 oftransistor base plate 130 has many transistors 131 arranged in an array,many capacitors 133 and many metal layers (not illustrated in thediagram) connected to the transistors 131. The color filter layer of thecolor filter base plate 110 has many color areas such as the red area111, the green area 113 and the blue area 115. Each color area of thecolor filter base plate 110 corresponds to one transistor 131 and onecapacitor 133 of the transistor base plate 130. The display panel 100displays an image on the display area A100 by controlling thetransistors 131 of each color area.

The buffering metal layer 170 positioned at the color filter base plate110 is exemplified below. The display panel 100 further comprises ablack matrix positioned on the inside surface 112 of the color filterbase plate 110. The black matrix used for blocking undesirable lightfrom entering the display area A100 is made of metal or resin. In thepresent embodiment, the black matrix is a metal black matrix, and thebuffering metal layer may comprise the metal black matrix. In thepresent embodiment of the invention, the buffering metal layer 170 asshown in FIG. 3 is a metal black matrix of the color filter base plate110.

The color filter mother substrate 1100 is cut as indicated in FIG. 2B.The predetermined laser cutting line L0 is a predetermined position forlaser cutting. The laser source for laser cutting is a carbon dioxide(CO₂) laser light whose wavelength is approximately 10.6 μm. The CO₂laser light whose wavelength corresponds to infrared light can be easilyabsorbed by the color filter mother substrate 1100 made of glass and ismore conducive to the process of heat treatment. According to thecutting method of the color filter mother substrate 1100, an initialcrack is first marked on the edge along the predetermined laser cuttingline L0. Next, the laser source heats along the initial crack. When thelaser source passes through the position corresponding to thepredetermined laser cutting line L0 of the color filter mother substrate1100, the molecular bonds of the glass of the color filter mothersubstrate 1100 will be broken along the predetermined laser cutting lineL0 due to the thermal heat of the laser source. Then, the brokenmolecular bonds are cooled down by a cooling system (not shown). Afterthe laser source has completely passed through the positioncorresponding to the predetermined laser cutting line L0 and the glasshas been cooled down, the color filter mother substrate 1100 will bedivided into two pieces.

Additionally, as shown in FIG. 2B, there is a third distance D150between the rim of the sealant 150 and the predetermined laser cuttingline L0, and the first distance D170 is smaller than the third distanceD150. The third distance D150 of FIG. 2B is substantially identical tothe third distance D150′ between the rim of the sealant 150 and the edge110′ of the color filter base plate 110 as indicated in FIG. 3. When thelaser source reaches the position point P0 of the predetermined lasercutting line L0, the heat generated from the laser source will beradiated from the position point P0. As the partial area 170 b of thebuffering metal layer 170 is projected outside the sealant 150, the area170 b of the buffering metal layer 170 is the first portion to receivethe thermal energy transmitted from the position point P0 via the colorfilter mother substrate 1100. The buffering metal layer 170 being ametal material has excellent heat conduction, so that the heat of thelaser source is transmitted from the area 170 b of the buffering metallayer 170 to the area 170 a. That is, most of the heat radiated from thecolor filter mother substrate 1100 is absorbed, transmitted anddissipated by the buffering metal layer 170. Thus, the buffering metallayer 170 is capable of protecting the sealant 150 and other organicmaterial from absorbing the heat and being damaged by the absorbed heat.

Normally, the third distance D150 between the rim of the sealant 150 andthe predetermined laser cutting line L0 ranges between about 300˜500 μm.In the embodiments of the invention, the first distance D170 between therim of the buffering metal layer 170 and the predetermined laser cuttingline L0 is at least about 5 μm, or is in a preferable range of about5˜300 μm, 5˜200 μm, or 5˜100 μm. When the invention is applied forlaser-cutting a thin base plate, or applied in a structural design withvery narrow the third distance D150 between the rim of the sealant 150and the predetermined laser cutting line L0, the first distance D170between the rim of the buffering metal layer 170 and the predeterminedcutting line L0 could preferably range between about 5˜20 μm to avoidthe sealant or the organic material disposed close to the cutting linebeing damaged by laser heat.

<Disposition of Buffering Metal Layer on Color Filter Mother Substrate>

When a buffering metal layer and a sealant are disposed on a colorfilter mother substrate, the relative relationship between the bufferingmetal layer and the sealant is disclosed below. Referring to FIG. 4, atop view of the buffering metal layer and the sealant of the firstembodiment of the invention on a color filter mother substrate is shown.A color filter mother substrate 3100 is divided into many color filterbase plates 110, 310 and 510 along the predetermined laser cutting linesL0, L1 and L2. The patterns of the buffering metal layers disposed onthe color filter base plate 110, 310 and 510 could be the same ordifferent. For example, the buffering metal layer 170 at the colorfilter base plate 110 is a rectangular-frame metal layer, and thesealant 150 is disposed along the inner side of the rectangular-framebuffering metal layer 170. In the color filter base plate 310, thebuffering metal layer 370 has four metal strips disposed around thecolor filter base plate 310, the width of the buffering metal layer 370is sufficient for covering the width of the sealant 150, and there is adistance between the inner edge of the sealant 150 and the inner side370′ of the buffering metal layer 370. In the color filter base plate510, the buffering metal layer 570 includes many separate metalsegments. The sealant 150 is disposed inside the metal segments of thebuffering metal layer 570. The color filter mother substrate 3100 cutinto the color filter base plates 110, 310 and 510 with differentstructural designs is taken for the exemplifications; however, theinvention is not limited thereto. The color filter mother substrate canalso be cut into many color filter base plates with identical structuraldesigns.

Therefore, any buffering metal layer 170 whose rim is closer to thepredetermined laser cutting line L0 than the rim of the sealant 150 (asshown in FIG. 2B) so that the heat generated during laser cutting can beabsorbed, transmitted and dissipated for protecting the sealant 150 canbe used as the buffering metal layer of the embodiments of theinvention. As indicated in FIG. 4, there are three design patternsregarding to the shape of the buffering metal layer and the relativeposition between the buffering metal layer and the sealant. Anyone whounderstands the technology of the invention can make necessaryadjustments and modifications to fit actual needs in practicalapplications, and the present invention is not limited to the patternexemplifications in FIG. 4.

<Disposition of Buffering Metal Layer on Transistor Mother Substrate>

Moreover, the buffering metal layer 170 of FIG. 3 could be disposed onthe color filter base plate 110 as disclosed above, or formed on theinside surface 132 of the transistor base plate 130. That is, thebuffering metal layer 170 is positioned between the transistor baseplate 130 and the sealant 150. The cross-sectional structure andcharacteristics of the buffering metal layer 170 positioned on theinside surface 132 of the transistor base plate 130 are the same as thebuffering metal layer 170 formed on the color filter base plate 110, andare not repeatedly described here.

When a buffering metal layer and a sealant are disposed on a transistormother substrate, the relative relationship between the buffering metallayer and the sealant is disclosed below. FIG. 5 is a top view of thebuffering metal layer and the sealant formed on a transistor mothersubstrate according to the first embodiment of the invention. Thetransistor mother substrate 3300 may be cut into many identical ordifferent transistor base plates along the predetermined laser cuttinglines L0 and L2. In the present embodiment of the invention, thetransistor mother substrate 3300 is cut into many different transistorbase plates 130, 330 and 530. The relative position between each of thebuffering metal layers 170, 370 and 570 and the sealant 150 is the samewith the color filter mother substrate 3100 of FIG. 4 and is notrepeatedly described here.

The transistor base plates 130, 330 and 530 respectively havecorresponding IC bonding areas 130 a, 330 a and 530 a. It is noted thatthe transistor mother substrate 3300 of FIG. 5 differs from the colorfilter mother substrate 3100 of FIG. 4 in that the transistor mothersubstrate 3300 of FIG. 5 does not have the predetermined laser cuttingline L1 like the color filter mother substrate 3100 of FIG. 4. Also, theIC bonding area 130 a, 330 a and 530 a of the transistor mothersubstrate 3300 of FIG. 5 have electrical pads and need wires forelectrical connecting. Thus, the buffering metal layers 170, 370 and 570are not disposed on the side near the IC bonding areas 130 a, 330 a and530 a, that is, the side 150′ of the sealant 150. As indicated in FIG.3, after cutting, the IC bonding area 130 a of the transistor base plate130 of the display panel 100 is projected more than the color filterbase plate 110 is.

According to the display panel and the mother substrate thereofdisclosed in the first embodiment of the invention, the partial area 170b of the buffering metal layer 170 is disposed outside the sealant 150to protect the LCD mother substrate 1000 during laser cutting and avoidsthe sealant 150 being damaged by the heat provided by the laser source.Preferably, the buffering metal layer 170 is a metal black matrix forthe color filter base plate 110 and the transistor base plate 130. Thebuffering metal layer 170 not only protects the sealant 150 but alsoblocks undesirable light from entering the display area A100.

Second Embodiment

The LCD panel and the mother substrate thereof of the second embodimentof the invention differ from that of the first embodiment in that theblack matrix of the second embodiment of the invention is a resin blackmatrix. As for other similarities, the same designations are used andare not repeatedly described here.

Referring to FIG. 6, a cross-sectional view of an LCD mother substrateclose to a predetermined laser cutting line according to the secondembodiment of the invention is shown. The LCD mother substrate 7000could be cut into many display panels 700. The LCD mother substrate 7000further comprises a color filter mother substrate 7100, a transistormother substrate 7300, a sealant 150, a resin black matrix 750 and abuffering metal layer 770. Each of the color filter mother substrate7100 and the transistor mother substrate 7300 has a predetermined lasercutting line L70. The sealant 150 is disposed between two mothersubstrates 7100 and 7300 and positioned on the inner side of thecorresponding predetermined cutting line L70. There is a first distancebetween D770 between the rim of the buffering metal layer 770 and thepredetermined cutting line L70. The resin black matrix 750 is an organicmaterial which may easily be damaged by laser heat.

In the present embodiment of the invention, the buffering metal layer770 is formed on the inside surface 7100′ of the color filter mothersubstrate 7100 and on the inside surface 7300′ of the transistor mothersubstrate 7300 for illustration.

Please refer to the color filter mother substrate 7100 of FIG. 6. Theresin black matrix 750 is positioned on the inside surface 7100′ of thecolor filter mother substrate 7100, and the resin black matrix 750positioned between the sealant 150 and the color filter mother substrate7100 is separated from the color filter mother substrate 7100 by thebuffering metal layer 770. The resin black matrix 750 disposed on theside of the color filter mother substrate 7100 is used for blocking thelight from entering the display area of the display device 700. There isa second distance D750 between the rim of the resin black matrix 750 andthe predetermined laser cutting line L70, and the first distance D770 issmaller than the second distance D750. The second distance D750 issubstantially identical to the third distance D150 between the rim ofthe sealant 150 and the predetermined laser cutting line L70. Thepartial area 770 b of the buffering metal layer 770 is projected fromthe resin black matrix 750 to protect the resin black matrix 750 frombeing damaged by the heat provided by the laser source during lasercutting.

Besides, the LCD mother substrate 7000 further comprises an organicprotection layer (such as an overcoat) 790 positioned on the insidesurface 7100′ of the color filter mother substrate 7100. The partialarea 790 a of the organic protection layer 790 positioned between thesealant 150 and the color filter mother substrate 7100 is separated fromcolor filter mother substrate 7100 by the buffering metal layer 770. Thebuffering metal layer 770 is used for protecting the partial area 790 aof the organic protection layer 790 corresponding to the sealant 150from being damaged by the heat generated from the laser source duringlaser cutting.

Moreover, the structure and relative relationship among the bufferingmetal layer 770, the resin black matrix 750 and the organic protectionlayer 790 of the transistor mother substrate 7300 refer to theelaboration of the color filter mother substrate 7100 disclosed above.For example, the organic protection layer 790 is positioned on theinside surface 7300′ of the transistor mother substrate 7300, and thepartial area 790 a of the organic protection layer 790 positionedbetween the sealant 150 and the transistor mother substrate 7300 isseparated from the transistor mother substrate 7300 by the bufferingmetal layer 770, and other similarities are not repeatedly describedhere.

Please refer to both FIG. 6 and FIG. 7. FIG. 7 shows a partialcross-sectional view of a single LCD panel formed by cutting the LCDmother substrate of the second embodiment of the invention. Many displaypanels 700 are obtained after laser cutting the LCD mother substrate7000 along the predetermined cutting line L70 of FIG. 6. After lasercutting, the original position of the predetermined laser cutting lineL70 of FIG. 6 corresponds to the edge 700′ of the display panel 700 ofFIG. 7. There is a second distance D750′ (FIG. 7) between the rim ofresin black matrix 750 and the edge 700′ of the display panel 700. Thesecond distance D750′ is substantially identical to the second distanceD750 (FIG. 6) between the rim of the resin black matrix 750 and thepredetermined laser cutting line L70. After cutting, each display panel700 has many elements such as the resin black matrix 750 and the organicprotection layer 790, and relevant positions and connecting relationshipof these elements are the same as that in FIG. 6, and are not repeatedlydescribed here.

According to the display panel and the mother substrate thereofdisclosed in the second embodiment of the invention, a buffering metallayer 770 is disposed between a resin black matrix 750 and a base plateto avoid the laser heat from damaging the organic material (such as theresin black matrix 750 or the organic protection layer 790) disposedunder the base plate. The buffering metal layer 770 of the presentembodiment of the invention has a partial area 770 b of the bufferingmetal layer 770 projected from the sealant 150 and the resin blackmatrix 750, so that the heat provided by the laser source is absorbed,transmitted and dispersed by the buffering metal layer 770. Thus, thebuffering metal layer 770 protects the resin black matrix 750, thesealant 150 and the partial area 790 a of the organic protection layer790 corresponding to the sealant 150 from being damaged by the heat. Thefirst distance between the rim of the buffering metal layer 770 and theedge of the base plate/predetermined cutting line, like the rangedisclosed in the first embodiment, is at least about 5 μm; for example,the first distance ranges between about 5˜300 μm, or about 5˜200 μm, orabout 5˜100 μm. When the invention is applied in a super thin base plateor when the distance between the rim of the sealant 150 and thepredetermined cutting line L70 is very tiny, the first distance betweenthe rim of the buffering metal layer 770 and the edge of the baseplate/predetermined cutting line could be preferably set to be about5˜20 μm.

According to the display panel and the mother substrate thereofdisclosed in the above embodiments of the invention, the edge of thebuffering metal layer is closer to the edge of the display panel thanthe sealant after laser cutting, so as to avoid the sealant beingdamaged by the heat. However, the buffering metal layer may further beused to protect other materials (such as the organic material) whichcannot resist the heat. Any designs enabling the partial area of thebuffering metal layer to be closer to the predetermined cutting line ofthe LCD mother substrate than these materials which cannot resist theheat so as to absorb the heat and protect these non-heat-resistingmaterials are within the scope of protection of the invention.

Furthermore, if a metal black matrix is adopted in the display panelstructure, the original manufacturing process of metal black matrix isincorporated with the concept of the buffering metal layer of theinvention to protect the non-heat-resisting materials. If a resin blackmatrix is adopted in the display panel structure, the buffering metallayer of the invention would be preferably formed between the resinblack matrix and the base plate for the purpose of protection.

According to the display panel and the mother substrate using the samedisclosed in the above embodiments of the invention, the buffering metallayer protects the organic material of the display panel from beingdamaged by the heat during the laser cutting of the LCD mothersubstrate. Particularly, when the transistor mother substrate or colorfilter mother substrate of the LCD mother substrate becomes thinner andthinner, or when the distance between the rim of the sealant LCD mothersubstrate and the predetermined laser cutting line becomes smaller andsmaller, the buffering metal layer of the invention is capable ofprotecting the sealant or other organic materials from being damaged bythe heat, so as to increase the production yield of the display panel.

While the invention has been described by way of examples and in termsof preferred embodiments, it is to be understood that the invention isnot limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

1. A liquid crystal display (LCD) mother substrate having a plurality ofLCD panels, and the LCD mother substrate comprising: two mothersubstrates opposite to each other, wherein the two mother substratescomprises a first mother substrate and a second mother substrate, eachmother substrate has an inside surface and an outer surface, the insidesurfaces of the mother substrates are opposite to each other, and theouter surfaces respectively have a predetermined cutting line; a sealantdisposed between the inside surfaces of the mother substrates andpositioned on the inner side of the corresponding predetermined cuttinglines; and a buffering metal layer formed on the inside surface of atleast one of the mother substrates and disposed along the sealant,wherein at least a portion of the buffering metal layer is positionedoutside the sealant, and there is a first distance between the rim ofthe buffering metal layer and the predetermined cutting line.
 2. The LCDmother substrate according to claim 1, wherein the buffering metal layeris positioned between the mother substrates and the sealant.
 3. The LCDmother substrate according to claim 1, wherein the first mothersubstrate and the second mother substrate respectively are a colorfilter mother substrate and a transistor mother substrate, the insidesurface of the color filter mother substrate has a color filter layer,and the inside surface of the transistor mother substrate has aplurality of transistors arranged in an array and a plurality of metallayers connected to the transistors.
 4. The LCD mother substrateaccording to claim 3, wherein the buffering metal layer is positioned onthe inside surface of the color filter mother substrate.
 5. The LCDmother substrate according to claim 1, wherein the first distance rangesbetween 5˜300 μm.
 6. The LCD mother substrate according to claim 1,wherein the first distance ranges between 5˜200 μm.
 7. The LCD mothersubstrate according to claim 1, wherein the first distance rangesbetween 5˜100 μm.
 8. The LCD mother substrate according to claim 1,wherein the first distance ranges between 5˜20 μm.
 9. The LCD mothersubstrate according to claim 3, wherein the buffering metal layercomprises a metal black matrix positioned on the inside surface of thecolor filter mother substrate.
 10. The LCD mother substrate according toclaim 3, wherein the buffering metal layer is positioned on the insidesurface of the transistor mother substrate.
 11. The LCD mother substrateaccording to claim 4, further comprising an organic material layerpositioned on the inside surface of the color filter mother substrate,and the organic protection layer is positioned between the bufferingmetal layer and the sealant.
 12. The LCD mother substrate according toclaim 11, wherein the organic material layer is a resin black matrix.13. The LCD mother substrate according to claim 12, wherein there is asecond distance between the resin black matrix and the predeterminedcutting line, and the first distance is smaller than the seconddistance.
 14. The LCD mother substrate according to claim 10, furthercomprising an organic protection layer positioned on the inside surfaceof the transistor mother substrate, and the organic protection layer ispositioned between the buffering metal layer and the sealant.
 15. TheLCD mother substrate according to claim 1, wherein there is a thirddistance between the rim of the sealant and the predetermined cuttingline, and the first distance is smaller than the third distance.
 16. TheLCD mother substrate according to claim 1, wherein the predeterminedcutting line is a predetermined position for laser cutting.